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Helicobacter pylori infects around 50% of the world's population and is associated with diverse pathologies. In the most severe cases, the bacterium causes peptic ulcers and gastric cancer. The interplay between H. pylori and the host's immune response may help to determine the specific outcome of the infection. To study the relationship between antibody subclasses and variation in immune recognition, we determined the immunoglobulin G1 and 2 (IgG1 and IgG2) titres of sera obtained from patients with different H. pylori-associated pathologies. IgG1 and IgG2 titres were determined by ELISA in 44 sera of patients with different H. pylori-associated diseases (peptic ulcer, bleeding peptic ulcers, gastric cancer and dyspepsia). Soluble proteins from lysates were obtained from 12 different clinical isolates from similar associated diseases. We found that soluble proteins from lysates of H. pylori strains (SPLHP) recognition patterns in these sera were highly variable. Overall, IgG2 titres were higher than the IgG1 titres in the infected patients. In particular, those with peptic ulcers showed marked elevation in IgG2/IgG1 ratios, while SPLHPs from dyspeptic patients resulted in high IgG1 titres. Our results reveal that correlation of antibody subclass titres with Th1/Th2 markers may aid pathology characterization and show a potential diagnosis that could be formally evaluated in other studies.

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Histochemical and morphometric analyses were performed to characterize the fibre-type composition of two forelimb muscles of the South American subterranean rodent Ctenomys talarum. The studied muscles were the triceps lateralis, an extensor of the elbow, and the teres major, a flexor of the shoulder. It was found that these muscles had an elevated proportion of fast oxidative-glycolytic (FOG) fibres, and lower proportions of slow oxidative (SO) and fast glycolytic (FG) fibres. This composition probably qualifies the teres major and triceps muscles to perform the sustained effort required in tunnelling excavation. The results were discussed considering published data on fibre-type composition of mammals having different modes of life and digging behaviour. We here suggest that C. talarum has the potential of generating forces linked to rapid, powerful movements during sustained periods by means of an elevated proportion of FOG fibres, together with osteological changes that result in a great mechanical advantage of the forelimb muscles.

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Objective: Characterize mortality and associated factors in Chilean prematures born < 32 weeks of gestational age (GA) and treated with exogenous surfactant. Method: Cohort of newborns (n = 2 868) registered between 1998-2005 in the database of the Surfactant National Program. The association of gestational and neonatal variables with mortality was estimated through survival analysis and logistic regression. Results: Global mortality was 35 percent, varying by GA from 86.7 percent (< 25 weeks) to 12.6 percent (32 weeks). There was a clear decrease of mortality during the study period, along with a fall in the gestational age and birth weight (BW) of the patients who died (1 021 g +/- 295 to 854 g +/- 258) and GA (27.7 +/- 2.1 to 26.5 +/- 23) during this period. Pulmonary hemorrhage (PH) was the most important factor associated to mortality, so we decided to stratify the analysis by this condition. In children with PH, the mortality estimated risk lower as the GA increased (OR= 0.73; CI95 0.57-0.93) and every 100 g of additional BW (OR= 0.74; CI95 0.63-0.88). Children not affected by PH also had their OR diminished with major GA (OR= 0.82; CI95 0.76-0.90) and more BW (OR= 0.84; CI95 0.79 - 0.89). In addition, the OR decreased with better Apgar 5 min score (OR= 0.80; CI95 0.75-0.85), use of prenatal corticoids (OR= 0.71; CI95 0.56-0.90) and was higher in boys (OR= 1.36; CI95 1.08-1.71). Conclusions: Mortality in premature newborns decreased 15 percent during this period. Inmaturity and extreme low birth weight factors constitute a challenge to improve survival and avoid further complications like PH.

Objetivo: Caracterizar la mortalidad y factores asociados en prematuros chilenos < 32 semanas de edad gestacional (EG) receptores de surfactante exógeno. Pacientes y Métodos: Cohorte de neonatos 1998-2005 (n = 2 868) de la base de datos del Programa Nacional de Surfactante. Se estimó la mortalidad y su relación con variables maternas, del embarazo y neonatales mediante análisis de sobrevida y regresión logística. Resultados: La mortalidad global fue 35 por ciento, variando por EG entre 86,7 por ciento (< 25 semanas) y 12,6 por ciento (32 semanas). La mortalidad descendió en el período, reduciéndose también el peso de nacimiento (PN) de los fallecidos (1 02 lg +/- 295 a 854 g +/- 258) y su EG (27,7 +/- 2,1 a 26,5 +/- 2,3). La hemorragia pulmonar (HP) fue el factor más importante asociado a mortalidad, por lo que se estratificó el análisis por esa condición. En niños con HP, cada semana adicional de EG disminuye el riesgo de morir (OR: 0,73; IC95 0,57-0,93), así como por cada 100 g de peso adicional (OR: 0,74; IC95 0,63-0,88). Sin HP, el riesgo disminuye con mayor EG (OR: 0,82; IC95 0,76-0,90), mayor PN (OR: 0,84; IC95 0,79-0,89), mejor puntuación Apgar 5 minutos (OR: 0,80; IC95 0,75-0,85) y uso de corticoide prenatal (OR: 0,71; IC95 0,56-0,90), siendo significativamente mayor en varones (OR: 1,36; IC(95)1,08-1,71). Conclusiones: En el período, la mortalidad en prematuros disminuyó en 15 por ciento. La inmadurez y extremo bajo peso de niños actualmente viables, plantean importantes desafíos para mejorar su sobrevida y evitar complicaciones, entre ellas, la HP.

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Background: Congenital hypothyroidism is one of the most frequent endocrine diseases of the newborn and requires an early diagnosis to avoid its deleterious effects on neurological and intellectual functions. Aim: To evaluate thyroid scintigraphy (TS) findings in newborns with congenital hypothyroidism (CH), detected in the national program of newborn screening, which is working in Chile since 1992. Material and methods : TS findings of 189 newborns with CH (68 percent female) were analyzed. Tc99m pertechnetate TS was performed at 19 ñ 11 days of life. The gland was classified as eutopic, ectopic or absence of contrast (AC). Eutopic glands were classified by visual and quantitative criteria as: normal, goiter and decreased contrast (DC). TS results were compared by gender and hormonal levels. Results: Forty seven percent of newborns had ectopy, 29.1 percent eutopy and 24.3 percent AC. Eutopic gland predominated in males (44.2 percent vs 22.7 percent) and ectopy was more frequent in girls (53.1 percent vs 32.8 percent, p <0.05). Newborns with AC had the most severe hormonal alterations, without gender differences. Newborns with normal TS had less hormonal alterations than those with goiter. Conclusions: TS allows an etiological classification of CH. Thyroid dysgenesis is the most frequent cause, most of which correspond to ectopy, especially in girls. Eutopic glands are present in one third of newborns with CH. Goiter predominates, especially in males

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Endosseous implants have been used as orthodontic anchorage in recent years. A 3-dimensional mathematical model was constructed that uses the finite element method, which simulated an endosseous implant and an upper canine with its periodontal ligament and cortical and cancellous bone. Levels of initial stress were measured during 2 types of canine retraction mechanics (friction and frictionless). The lower magnitude and more uniform stresses in the implant and its cortical bone were found to have a moment-force ratio (M/F) of 6.1:1, whereas the canine and its supporting structures exerted a M/F ratio of 10.3:1. On the basis of these results, when the anchor unit is an endosseous implant, it seems better to use a precalibrated retraction system without friction (T-loop) where a low load-deflection curve would be generated.

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A total of 186 infants suffering from dehydration due to acute diarrhea were studied and divided into two groups: 84 children were placed in group A and received the oral rehydration solution (ORS) recommended by the World Health Organization (WHO), know as ORS-90 and those placed in group B were given an ORS with 60 and 90 mmol/L of sodium and glucose, respectively, with an osmolality of 240 mOsm/kg (ORS-60). Seven patients from group A (8.3%) and two from group B (2.5%) could not be orally rehydrated and required intravenous rehydration. The children were divided according to their weight for their age into eutrophics, grade I malnutrition (10 to 25% deficit), grade II (26 to 40% deficit) and grade III (more than 40% deficit). In those patients who evolved favorably, the average rehydration time was 4.5 to 5.3 hours, independently from their nutritional state. In the same way, no important variations were seen in the average sodium and potassium serum levels once the dehydration was corrected, in either of the groups. Yet, both groups showed a persistence in hypokalemia and hyperkalemia seen when admitted, once the dehydration was corrected, demonstrating that the short time needed for the correction of the dehydration was insufficient to completely corrected the changes in serum potassium. Closer studies must be conducted on the hydric balance to adequately demonstrate if the new ORS-60 induces lesser losses through vomiting and feces when compared to the ORS-90 recommended by the WHO.

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A total of 186 infants, suffering from acute diarrhea were studied and divided into two groups: 84 children were placed in group A and given the ORS recommended by the World Health Organization which contains sodium and glucose at concentrations of 60 and 90 mmol/L respectively and an osmolality of 311 mOsm/kg (mmol/kg) (ORS-90). Group B included 82 children who received an ORS containing sodium and glucose at concentrations of 60 and 90 mmol/L respectively and with an osmolality of 240 mOsm/kg (mmol/kg) (ORS-60). Seven belonging to group A (8.3%) required intravenous rehydration due to the severity of the diarrhea (three cases), persistent vomiting (three cases) and paralytic ileus (one case), while only two cases belonging to group B (2.5%) required intravenous rehydration due to severe losses through feces (one case) and another due to paralytic ileus (one case). No differences were observed due to the variations in sodium concentrations among either of the groups of patients, whether that be in the natremias when admitted or once rehydrated, with a general tendency towards the correction of the hypernatremia or hyponatremia seen during admittance with both types of ORS. A similar situation was observed with the variations in serum potassium. The results obtained from this study show the different advantages of using an ORS with lesser sodium and glucose concentrations as well as minor osmolality with those from using the solution recommended by the World Health Organization, when a lesser index of failures is observed in the treatment of children with acute diarrhea with oral rehydration therapy. Yet before widely recommending its' use, it should be demonstrated that the new ORS induces lesser losses through feces during the rehydrating period in children dehydrated due to acute diarrhea.

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A clinical trial was conducted to compare the safety and efficacy of a new oral rehydration solution (ORS) with that of the ORS recommended by the World Health Organization (WHO). One hundred thirty infants with dehydration due to acute diarrhea were randomized into two groups: 68 infants received the WHO ORS containing sodium and glucose in a concentration of 90 and 111 mmol/L, respectively, and an osmolality of 311 mosm/kg (ORS-90); 62 infants received an ORS containing sodium and glucose in a concentration of 60 and 90 mmol/L, respectively, with an osmolality of 240 mosm/kg (ORS-60). Treatment failure was noted in seven infants (10.3%) in the ORS-90 group; the causes of failure were high stool output (three cases), persistent vomiting (three cases), and ileus (one case). Only one patient in the ORS-60 group (1.6%) was considered a failure because of high stool output. No significant differences were noted in the serum sodium levels in either group of patients, both in relation to the natremia seen on admittance or that seen after rehydration. A trend was observed toward correction of hypernatremia or hyponatremia with both types of ORS. A similar situation was observed with respect to the variations seen in serum potassium levels. The results from this study suggest that there may be clinical advantages of using an ORS with concentrations of sodium and glucose and a total osmolality lower than that of ORS-90, because of the lower incidence of treatment failures.

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Se presenta el caso de una paciente atendida en el Hospital Base Cayetano Heredia, que tuvo el diagnóstico de Lupus Eritematoso sistémico (LES) que en el curso de su enfermedad se complica con un pseudo-obstrucción intestinal. En relación con este caso, se revisaron todos lo pacientes del Servicio de Reumatología con diagnóstico de LES que presentaron complicación semejante, con resultados negativos; se revisa el tema sobre pseudo-obstrucción intestinal y el compromiso que el LES tiene sobre el tracto digestivo..

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